Rotary compressor



H. COANDA TURBOJET ENGINE HAVING JET PUMP AND ROTARY COMPRESSOR MEANS TO REDUCE TURBINE EXHAUST PRESSURE 4 Sheets-Sheet 1 Filed May 17, 1948 242 w )J E a m H S 1 l Il m 1 H. COANDA llllllt Dec. 30, 1952 TURBOJET ENGINE HAVING JET PUMP AND ROTARY COMPRESSOR MEANS TO REDUCE TURBINE EXHAUST PRESSURE Flled May 17, 1948 Dec. 30, 1952 I H. COANDA 2,523,356

TURBOJET ENGINE HAVING JET PUMP AND ROTARY COMPRESSOR MEANS TO REDUCE TURBINE EXHAUST PRESSURE Filed May 1?, 1948 4 sheets-sheet :5

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TURBOJET ENGINE HAVING JET PUMP AND ROTARY COMPRESSOR I MEANS TO REDUCE TURBINE EXHAUST PRESSURE Filed May 17, 1948 4 Shams-Sheet 4 CQOLEK Patented Dec. 30, 1952 UNITED STATES rarrm OFFICE TURBOJ ET ENGINE HAVING JET PUMP AND ROTARY COMPRESSOR MEANS TO BE- DUCE TURBINE EXHAUST PRESSURE Henri Coanda, Paris, France Application May 17, 1948, Serial'N0.I27,442 In France May'22, 1947 (C1. "GO-39.5)

proved manner.

It is, of course, well known that the proportion of the energy available in a gas or gaseous mixture which can be converted into useful work depends in part on the difference between'the pressure of the gas or mixture delivered to the engine and the pressure against which the gas leaving the engine is discharged. In accordance with the present invention, an engine, preferably a turbine, itself embodies a novel arrangement by which this pressure differential is increased.

An object of the invention is to provide a gas engine such as aturbine constructed to increase the inlet-discharge pressure differential by ar ranging the driven element of the engine to discharge substantially at or immediately upstream of the neck or throat of a converging-diverging nozzle or the like.

In the accompanying drawings showing representative embodiments of the invention:

Figure 1 is an axial, sectional View of an apparatus embodying the invention and including a centripetal flow turbine;

Figures 2, 3, 4 and 5 are cross sections, respectively, on the lines IIII, III-III, IVIV and VV of Figure 1;

Figure 6 isa view similar to Figurell but showing amodificationin which a supplemental compressor of the centrifugal type is embodied in place of the axial flow type compressor shown in Figure 1;

Figure 7 is a schematic, axial, sectional view of a modified construction;

Figure 8 shows two units embodying theinvention in axial section coupled to act simultaneously in connection with a central turbine; and

Figure. 9 is a schematic, axial, sectional view of an axial flow type turbineconstructed in accordance with the invention.

In the illustrative embodiment of the invention shown in Figures 1 to 5, there is shown an apparatus comprising a stationary structure generally designated A and including a combined compressor and outer turbine housing I, an inner turbine housing 2within the 'housing l,-and

a turbine housing section 3 shown as depending '2 from the lower end of the housing I, all of the sections 1, 2 and 3 being in axial alignment. Mounted within the stationary structure A is a rotor generally designated B comprising a multistage compressor unit 4, a turbine rotorelement 5, and a depending shaft 6, the'rotor B. being journaled in bearings I and 8. A supplemental compressor 9 has its rotor mounted on the lower end of the shaft 6.

The outer turbine housing I is formed with a plurality of axially aligned compressor stage housing sections 10, each containing-a compressor rotor ll forming part of the rotor structure 13 previously referred to. Hot gas from any -available source-for example, an engine-exhaust, the discharge of a system for cooling a mechanism or medium, or a combustion apparatus-4s adapted to be introduced into the upper end-of the compressor 4 through an inlet opening 12 so as to pass downwardly through the successive com pressor stages and be compressed andthcn delivered to the-turbine rotor 5 for operating the latter in a manner to be described later. During its passage through the successive compressor stages, the gas introducedinto theinlet opening 12 is cooled bytair flowing through heatexchange passages l3 surrounding the compressorstages I 0.

The turbine inner housing 2'is mounted inside of and in spaced relation to the outer turbine housing I, being supported in the outer housing by ducts is which communicate with the heat exchange passages [3. The space 15 between the inner housing 2 and outer housing .I is arranged to receivecompressed and partially cooled gas from the compressor 4. The inner housing 2 is formed with an internal space It which receives air from the heat exchange passages t3 and the ducts I4.

The inner turbine housing 2 is formed to provide an annular section H surrounding the turbine rotor 5, the section ll being provided around its periphery with inlets 13 through which compressed gas may enter the section I! fromthe space .15. Radially inward of the space ll are converging nozzles lilarranged to dischargecompressed gas inwardly to impinge upon and operate the turbine rotor 5. Spaced a little inwardly of the nozzles 19 are the exit edges of a plurality of blades 26 which provide other converging nozzles 2! through which air from the passages I3 and ducts l4, heated by heat exchange from the gas being compressed, is discharged to intermix with the gas discharged by the nozzles [9.

The discharge or outlet of the turbine, "is defined by a section curved as-at 22 so as to merge with the throat 23 of a converging-diverging noz zle 24. At the zone of merging of the converging part 22 with the nozzle throat 23, is an annular stator nozzle 25 characterized by having the continuation or extension of one surface, e. g., its lower surface or lip, forming the wall of the converging part or throat 23 of the nozzle 25'. Compressed gas, partially cooled by the air flowing through the heat exchange passages l3, flows from the spac l through the annular nozzle 25' into the throat 23 of the converging-diverging nozzle 25, and passes downwardly through the nozzle 25. Because of the characterizing shape or arrangement of the annular nozzle 25 with respect to the converging-diverging nozzle 24, a low pressure zone or area created in the throat 23 is established immediately downstream of the discharge or downstream side of the turbine rotor 5. As a result, the pressure against which the rotor 5 discharges is reduced, thus increasing the inlet-discharge pressure differential and consequently increasing the capacity of the turbine 5 to convert energy in the gas entering at 12 into useful work.

In the embodiment shown in Figure 1, the mixture of air and gas passing downwardly through the nozzle structure 24 and expanding at the lower end thereof is recompressed by the supplemental compressor 9, and is then discharged at 25 for transmission to any desired apparatus or equipment for using the energy available in the recompressed mixture.

Figure 6 shows a construction the same as that shown in Figures 1 to 5, inclusive, with the exception that the Figure 6 construction includes a centrifugal type re-compressor 9 in place of the axial flow type re-compressor 9 shown in Figure 1. The operation of the Figure 6 construction is generally similar to the operation described with reference to Figures 1 to 5.

The modified construction shown in Figure 7 includes a turbine housing 27, a rotor 28 mounted on a shaft 29 extending through a convergingdiverging nozzle 30, and a centrifugal compressor 3!, the turbine and compressor rotors and the shaft 29 being mounted in bearings 3233.

The housing 21 includes a generally annular chamber 34 adapted to receive hot air or gas through an inlet connection 35. The chamber 34 is formed with inner surfaces 3fi35 which converge so as to lead to a restricted annular discharge passage 37 disposed at the periphery of the turbine rotor 28.

The housing 21 is formed at one side of the turbine rotor 28 (at the left as viewed in Figure '7) with a chamber 38 provided with an inlet opening 39 for the introduction of compressed air or gas from any suitable source, for example, from a compressor (not shown) driven by an extension of the shaft 29. The peripheral wall of the chamber 38 separates the chamber 38 from the annular chamber 34, and provides the converging inner surface 36 of the chamber 34 previously referred to. This peripheral wall is formed with a slot 50 which is so shaped that its downstream wall or surface, i. e., its wall or surface nearest the passage 21, merges with the converging surface 36 leading to the passage 31.

On the downstream side of the central plane of the rotor 28, that is, on the right hand side as. shown in Figure '7, the housing 2! is formed with an annular chamber ll having an opening 42 for the inlet of compressed air or gas from any suitable source, such as the source from which air is supplied to the inlet opening 39 leading to the chamber 38. The peripheral wall of the chamber 4| separates the chamber 4| from the annular chamber 34, and provides the converging surface 35 previously referred to as leading toward the passage 37. This peripheral wall is formed with a slot 43, the downstream wall or surface of which--that is, the wall or surface nearest the passage 2'imerges with the associated surface 35 converging upon the passage 31.

The inner wall es of the chamber M converges in a downstream direction from the passage 3? toward the axis of the turbine so as to merge with the neck or throat 45 of the convergent-divergent nozzle 35!, which is constituted by the wall 44, the throat45, and an expanding or diverging section 46. A straight section 41 is shown as being interposed between the diverging section 46 and the centrifugal compressor 3|.

In operation, hot air or gas is delivered through the inlet opening 35 to the annular chamber 34 so as to flow through the nozzle passage 31 and impinge on the turbine rotor 23 for driving the latter, the shaft 29, and the supplemental compressor 3i. Compressed air is delivered to the chambers 38 and ii through the inlets 39 and 42, respectively, so as to flow through the slots 40 and d3 convergingly along the walls 35 and 35 of the chamber 35 in intermixture with the hot air or gas. The mixed hot air or gas and air from the chambers 34, 38 and ll will be discharged on the downstream side of the rotor so as to pass through the neck or throat 45 of the convergingdiverging nozzle 35, thereby creating a zone of reduced pressure in the throat 55 immediately downstream of and adjacent the rotor 28. In this manner the turbine exhaust pressure is reduced and the inlet-discharge pressure differential is increased. The gas and air mixture, recompressed by the centrifugal compressor 3|, may then be led from a discharge passage 48 to apparatus or equipment selected for deriving useful work or effect from the recompressed mixture.

Figure 8 shows an arrangement in which two units AA constructed in accordance with the invention are associated cooperatively for driving a turbine B. Air supplied to the units AA' for a purpose to be described is compressed by a pre-compressor C.

The units AA' are of identical construction. Each includes a turbine housing generally designated 55, a rotor 55 mounted on a shaft 5!, and a re-compressor 52 also mounted on the shaft 5| which extends through a converging-diverging nozzle structure 55.

The turbine housing 49 is equipped with an inner casing or housing 54 formed to provide an annular nozzle 55 surrounding the periphery of the rotor 50. Hot air or gas delivered to the inner casing 54 may be reheated by the introduction of a combustible by means not shown.

The inner casing 54 is surrounded by an annular outer housing part 55 arranged to receive air through a passage 57, the air preferably bein heated in a manner to bedescribed. The casing 51 is formed with inner surfaces 58-59 which converge to form a neck or throat into which the nozzle 55, referred to above, discharges. On the discharge or downstream side of the rotor 50, the housin 56 is formed with a surface 60 which converges toward the axis of the turbine and extends downstream with respect to the turbine rotor so as to merge with the throat of the nozzle structure 53, which is constituted by the surface [it], the throat 6|, and a diverging section 62. A straight section .63 is interposed betweenthe diverging section GZand'the re-compressor 52.

In this arrangement, as in the arrangement shown in Figure 1, the turbine rotor periphery is disposed substantially at the throat or neck of a convergent-divergent passage provided by the converging surfaces 585il and the diverging surfaces 60, previously referred to,-and 64, the latter being constituted by the downstream side of the rotor 5|] itself.

Downstream of the rotor 50, the turbine housing 49 is formed witha toroidal chamber 65 having an inlet connection 66 through which air, precompressed by the equipment C and cooled by a heat exchanger 67, is introduced. The radially inner part of the wall of the chamber 65 is provided with a passage or slot 88 which is arranged similarly to the slot 25 shown in Figure 1. The continuation of extension of the downstream wall orsurface of the slot 68 merges with the surface 60 and the throat 6| of the converging-diverging nozzle 53.

In operation, air pare-compressed by the equipment C is delivered through the passage 66 and heat exchanger 61 to the toroidal passage 65. This air, heated by the pre-compression, is cooled in passing through the heat exchanger 67, giving up heat to the air or gas flowing in through the passage 5'! to the interior of the turbine housing section 56. The hot air and gas mixture discharged from the housing section 56 and the interior casing 54 through the nozzles 55 impinges on the rotor 50, driving the latter and operating the re-compressor 52. Airflowing from the toroidal chamber 65 through the slot 68 and in the direction indicated by the arrows in Figure 8 increases the velocity and hence lowers the pressure of the air and gas mixture in the throat 6| of the convergent-divergent nozzle structure, thereby producing a reduced pressure zone immediately downstream of the turbine rotor 5B, and thus increasin the inlet-discharge pressure differential.

The mixture of air and gas re-compressed by the supplemental compressor 52 acts upon the turbine B so as not only to operate the precompressor 0, but also to provide useful work. As shown in Figure 8, both units AA operate in connection with the single precompressor C and turbine 13', the total power delivered to the latter being the sum of the power outputs of the units A'-A.

Figure 9 illustrates schematically an axial flow turbine construction embodying the invention. In general, the construction includes a housing 69, and a rotor 10 equipped with peripheral blades H through which the hot air or gas flows parallel to the axis of rotation.

The hot air or gas may be introduced through an inlet opening 12 so as to flow into a chamber 13 shown above the rotor ill in Figure 9. The chamber 73 is defined by wall sections 14 and 15 which converge to form a neck or throat 16 at the zone of the rotor blades ll. Downstream of the blades H are casing walls 11 and T8 definin a generally annular discharge passage or chamber 19. The walls 13 first are divergent with respectto the wall 11, and then converge so as to merge with the throat or neck 80 of a converging-diverging nozzle structure 8i constituted by the wall section 18, the throat or neck 80, and a divergent section 82.

A separate chamber 83 surrounds the convergent-divergent wall 18, and is adapted to receive compressed airor gas through openings 84-84 from a compressor which may be similar to the compressor 9 shown in Figure 1 and the compressor 52 shown in Figure 8. The compressor may be driven by the shaft 85 of the turbine rotor 10.

The wall sections 18 are formed with slots 86 arranged similarly to the slots 25 shown in Figure 1. Thus, the continuations of the downstream sides or surfaces of the slots 86 merge with the throat of the convergent-divergent nozzle structure 8!. By virtue of this arrangement, a zone of reduced pressure is created immediately downstream of the turbine blades H, or, otherwise stated, the inlet-discharge pressure diiferential is increased.

The constructions illustrated by way of example embody the invention in preferred forms, but it isintended that the disclosure be illustrative rather than definitive, the invention being defined in the claims.

What I claim is:

1. In apparatus for converting heat energy contained in a gas into work, a gas engine comprising a stator, a movable element therein drivable by said gas, a gas inlet in said stator through which gas is supplied to drive said element, and an outlet in said stator; a convergingdiverging nozzle, said outlet being defined by a section which converges so as to merge with the throat of said converging-diverging nozzle; annu lar nozzle means extending through said converging-diverging nozzle having one surface which defines said annular nozzle means continued to form the wall of said throat of said convergingdiverging nozzle; a supplemental compressor for re-compressing the gas discharged through said converging-diverging nozzle; and means .for directing gas to flow through said other nozzle means into said converging-diverging nozzle and through said throat thereof in a direction away from said outlet-defining section to thereby create in said throat and consequently in said outlet a region of reduced pressure.

2. In apparatus for converting heat energy contained in a gas into work, a gas engine comprising a stator, a movable element therein drivable by said gas, a gas inlet in said stator through which gas is supplied to drive said element, and an outlet in said stator; a converging-diverging nozzle, said outlet being defined by a section which converges so as to merge with the throat of said converging-diverging nozzle; annular nozzle means extending through said convergingdiverging nozzle having one surface which defines said annular nozzle means continued to form the wall of said throat of said converging-diverging nozzle; means for directing gas to flow through said other nozzle means into said converging-diverging nozzle and through said throat thereof in a direction away from said outlet-defining section to thereby create in said throat and consequently in said outlet aregion of reduced pressure; means driven by said engine for precompressing the gas before it is delivered to said inlet; means for conducting part of the gas away from said inlet and to said other nozzle means for flow therethrough into said converging-diverging nozzle throat; heat exchange means through which air is passed for cooling the precompressed gas; and means for delivering a portion of the air from said heat exchange means for mixing with the gas supplied for driving said element and for delivering another portion of said air from said heat exchange means to said other 7 nozzle means for fiow therethrough into the throat of said converging-diverging nozzle.

3. In apparatus for converting heat energy contained in a gas into work, a gas turbine including a stator, a rotor therein, a gas inlet in said stator, means for directing gas from said inlet to impinge on said rotor for driving the latter, and an outlet in said stator coaxial with and immediately adjacent said rotor; a converging-diverging nozzle coaxial with said rotor, said outlet being defined by a section which converges from a zone relatively near the periphery of said rotor inwardly towards the rotor axis and away from said rotor and merges with the throat of said. converging-diverging nozzle; annular nozzle means extending through said converging-diverging nozzle having one surface which defines said annular nozzle means continued to form the wall of said throat of said converging-diverging nozzle; and means for directing gas to flow through said other nozzle meam into said converging-diverging nozzle and through the throat thereof in a direction away from said outlet-defining section to thereby create in said throat and consequently in said outlet a region of reduced pressure.

4. Apparatus as set forth in claim 3 including means for pro-compressing the gas before it is delivered to said inlet.

5. Apparatus as set forth in claim 3 including means for pre-compressing and cooling the gas before it is delivered to said inlet.

6. Apparatus as set forth in claim 3 including means for conducting part of the gas away from said inlet and to said other nozzle means for flow therethrough into said converging-diverging nozzle throat.

'7. Apparatus as set forth in claim 3 in which said outlet defining section forms a part of said stator and also forms the converging part of said converging-diverging nozzle.

8. Apparatus as set forth in claim 3 including a supplemental compressor for re-compressing the gas discharged through said converging-diverging nozzle.

9. Apparatus as set forth in claim 3 including means driven by said turbine for pre-compressing the gas before it is delivered to said inlet; means for conducting part of the gas away from said inlet and to said other nozzle means for flow therethrough into said converging-diverging nozflow therethrough into the throat 01 said converging-diverging nozzle.

10. Apparatus as set forth in claim 3 in which the means for directing gas to impinge on the said rotor comprises annularly extending nozzle means, said apparatus including further: means for pro-compressing the gas before delivery thereof to said annularly extending nozzle means; air passage means for conducting air in heat exchanging relation to the pre-oompressed gas; and still further nozzle means for discharging air from said air passage means to impinge on said rotor intermixed with the gas discharged by said annularly extending nozzle means. I

11. In apparatus for converting heat energy contained in a gas into work, a gas turbine including a stator, a rotor therein, a gas inlet in said stator, means for directing gas from said inlet to impinge on said rotor for driving the latter, and. an outlet in said stator coaxial with and immediately adjacent said rotor; and a converging-diverging nozzle coaxial with said rotor, said outlet being defined by a section which converges from a zone at the periphery of said rotor inwardly towards the rotor axis and axially away from said rotor and merges with the throat of said converging-diverging nozzle, said converging outlet section being the converging part of said converging-diverging nozzle, whereby a region of low pressure is created in said throat immediately downstream of said turbine rotor.

HENRI COANDA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,180,403 Leblanc Apr. 25, 1916 1,552,327 Martellone Sept. 1, 1925 2,055,026 Cook Sept. 22, 1936 2,147,200 Kadenacy Feb. 14, 1939 2,211,795 Sauer Aug. 20, 1940 2,230,666 Martin Feb. 4, 1941 2,382,564 Haverstick Aug. 14, 1945 2,437,546 Meripol Mar. 9, 1948 2,458,600 Imbert Jan. 11, 1949 FOREIGN PATENTS Number Country Date 3,061 Great Britain Feb. 8, 1906 118,650 Great Britain Sept. 12, 1918 182,893 Great Britain July 10, 1922 363,382 Great Britain Dec. 14, 1931 372,104 Great Britain May 5, 1932 572,724 Great Britain Oct. 22, 1945 

